- 著者
-
古野 秀実
- 出版者
- 九州歯科学会
- 雑誌
- 九州歯科学会雑誌 (ISSN:03686833)
- 巻号頁・発行日
- vol.23, no.3, pp.221-233, 1969
- 被引用文献数
-
2
The development of the teeth of Ayu, Plecoglossus altivelis and its morphological and histological structures were studied. The total length of the fish ranged from 20mm to 174mm. The fishes in the present study were selected from the collection of Yamaguchi prefecture fishery laboratory. The results obtained are summarized as follows. 1. Growth and development of tooth germs. Comb-like tooth germ was shown to grow in fishes of approximately 20mm length. Pterygoid tooth germ was shown to grow in fishes of 22-28mm, and premaxillary, dentary and glossohyal tooth germs were shown to grow in 30-34mm length. 2. Eruptions. Pterygoid and glossohyal teeth erupted in fishes of 36-38mm in length. Comb-like and dentary teeth erupted in fishes of 45-47mm. Premaxillary tooth erupted in fishes of 60-66mm. 3. Numbers of the teeth. Comb-like teeth groups counted 13-14 in one quadrant of jaw. There were seen 13-19 teeth on the premaxillary, and over 30 teeth were seen on the pterygoid. There were counted 13-18 teeth on the glossohyal, and counted maximum 5-7 teeth on the dentary. 4. Formation of tooth germs. The initial stage of growth as observed in tooth germs of comb-like, pterygoid, premaxillary, dentary and glossohyal teeth was similar to that seen in mammals. 5. Enamel pulp. In each tooth germs of enamel organ, inner and outer enamel epithelium always contacted one another, therefore there was been not observed such enamel pulp, as seen in the mammalian tooth germ. 6. Enamel. Comb-like and premaxillary teeth had tubular enamel which was nomally penetrated by tubules from the dentin. Pterygoid, dentary and glossohyal teeth had hyaline enamel. 7. Dentin. Comb-like and premaxillary teeth had orthodentin. Pterygoid, dentary and glossohyal teeth had homogenous dentin. 8. The attachment of teeth. Premaxillary tooth was fibrous attachment of tooth to bone. Comb-like, pterygoid, dentary and glossohyal teeth were attachment by ankylosis.